1. Field of the Invention
The invention relates to a loudspeaker cone, particularly, to a loudspeaker cone which has an annular suspension member made of a laminate having a foam layer covered and strengthened by a cloth layer.
2. Description of the Related Art
It is known in the art to connect a voice coil 7 to a loudspeaker cone 1xe2x80x2 and to connect the outer marginal edge of the loudspeaker cone 1xe2x80x2 with a suspension rim 2xe2x80x2, as shown in FIG. 1, so as to mount the loudspeaker cone 1xe2x80x2 on a support frame via the suspension rim 2xe2x80x2. Typical materials suitable for making suspension rims include paper, rubber, textile materials, and foams. However, paper is prone to be torn at higher tones or higher amplitude vibrations due to its insufficient strength, and the durability thereof is low in humid environments so that high output power is impossible when paper is used in a suspension rim. Textile materials possess better strength and better formability than paper. But, as resins impregnating the textile materials are of less resiliency and flexibility, sound distortion of sound can occur at high output powers. While foams offer good response to high output powers and low frequencies as compared to paper and textile materials, they have poor strength and low humid-resistance and are susceptible to damage by insects and environmental factors. In addition, foams are color-degradable due to environmental conditions. Rubber works excellently at low frequencies, but has poor response to high frequencies. Moreover, it is prone to degradation due to temperature changes.
An object of the present invention is to provide a loudspeaker cone with a suspension member which is strong, durable, and flexible but still exhibits smooth response to different frequency ranges and minimizes distortion.
According to the present invention, a loudspeaker 10 comprises: a loudspeaker cone having an outer marginal edge; and an annular suspension member of laminated structure, connected to the outer marginal edge and adapted to support the loudspeaker cone on a support frame. The annular suspension member includes a layer of cloth and a first layer of flexible plastic foam integrally bonded to the layer of cloth. The first layer of foam has an inner surface in contact with the outer marginal edge, and the layer of cloth covers an outer surface of the first layer of foam opposite to the inner surface. Preferably, the suspension member further has a second layer of foam between the cloth and the first layer of foam, which is thinner than the first layer of foam. The thickness of the second layer of foam is preferably less than 5 mm.